Double twist spindle and method of twisting

ABSTRACT

THE SPECIFICATION DISCLOSES A DOUBLE TWIST SPINDLE, AND A METHOD OF TWISTING, IN WHICH YARN IS FED VIA A YARN TENSIONING MEANS TO THE INLET OF A CONTINUOUS CONDUIT CONNECTED TO THE ROTOR OF THE SPINDLE, THE OUTLET OF SUCH CONTINUOUS CONDUIT BEING DISPOSED OUTSIDE A PACKAGE FROM WHICH YARN IS BEING WITHDRAW. ROTATION OF THE CONTINU-   OUS CONDUIT CAUSES FONTROLLED ASPIRATION OF THE YARN, WHICH, UPON LEAVING THE CONDUIT DESCRIBED AN ENCLOSED ARC AROUND A SHELL MEMBER BEFORE PASSING THROUGH A YARN GUIDE.

Jill 1971 J. AUCAGNE ETAL 3,557,541

DOUBLE TWIST SPINDLE AND METHOD OF TWISTING' Filed 001}. 25, 1968 2 Shets-$heet 1 I 'lnve nlori Jaw Aucaqna Han-o. Felix 37 wmnwbdwu Attorney;

Jan. 26, 1971' J. AUCAGNE ETAL 3,557,541

DOUBLE TWIST SPINDLE AND METHOD OF TWISTING Filed Oct. 25, 1968 2 Shee ts-Sheet 2 000 M n U098 W mmlh w 0 I50"... m L

n w J w United States Patent O 3,557,541 DOUBLE TWIST SPINDLE AND METHOD OF TWISTING Jean Aucagne, Lyon, and Pierre Felix, Miribel, France,

assignors to Societe Rhodiaceta, Paris, France, a French body corporate Filed Oct. 25, 1968, Ser. No. 770,769 Claims priority, application France, Oct. 25, 1967, 125,840 Int. Cl. D01h 1/10, 7/86 US. Cl. 57--58.86 8 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to a double twist spindle and a method of twisting.

It is well known that for double twist spindles to be used economically they should be rotated at the highest possible velocity. However, if this is done, mechanical and dynamic problems are encountered which are difiicult to solve.

Attempts have been made to eliminate excessive ballooning, which results in a considerable degree of tension due to air resistance. In order to diminish the size of the balloon, it has been proposed to take up the yarn on an accumulating ring, in such a manner that the distribution of the yarn reaching a balloon is effected substantially in the plane of emergence of the yarn.

According to one aspect of the present invention, there is provided a double twist spindle comprising a hollow shaft forming a support for a yarn package, yarn tensioning means at the inlet to said shaft, a rotor rotatable with respect to a package supported on said shaft, about the axis of said shaft, a continuous conduit rotatable with said rotor and positioned to receive yarn fed from said package via said inlet, the outlet to said continuous conduit being positioned radially outwardly of said shaft, and a take-up member carried by the rotor between the hollow shaft and the outlet of said continuous conduit, whereby yarn leaving said outlet describes an enclosed are about said take-up member.

The expression continuous conduit is to be understood to mean a conduit, of a continuous character, which is in no way interrupted by anything in the nature of a slot, orifice or the like, which results in an appreciable drop in the negative pressure caused by the rotation of the spindle. The tensionig means may be of any desired type, such as the ball-type, or preferably the magnetic tensioning type, since the latter has a low degree of inertia.

The rotor may of a cup-shaped form, having an axially extending hollow shank, the continuous conduit being formed, at its upstream portion, by the hollow shank, and at its downstream portion, by at least one tube connected thereto and conforming to the shape of the cup-shaped member.

Advantageously, in order to ensure improved balance of the spindle, and in order to achieve, for the same spindle speed, different negative pressures in the continuous conduit, the latter is preferably constituted by a plurality of tubes disposed at equi-angular intervals relative to the spindle axis. The yarn aspiration value for a given speed of rotation of the spindle may be regulated in accordance with the operational conditions to be employed, simply by blocking one or more of such plurality of tubes.

The invention also provides a method of double twisting a yarn in which the yarn is fed through a hollow rotatable spindle and passed through a yarn guide to form a balloon, comprising regulating the tension of the yarn at the inlet to said spindle, effecting controlled aspiration of the yarn in said spindle, and taking up the yarn on a take-up member in such manner that the yarn describes thereon an encircled arc of between a quarter of a turn and one turn.

In order that the invention may more readily be understood, the following description is given, merely by way of example, reference being made to the accompanying drawings, in which:

FIG. 1 is a schematic cross-section of the one embodiment of double twist spindle according to the present invention;

FIG. 2 is a schematic fragmentary view of a modified form or spindle according to the invention; and

FIG. 3 is a graph illustrating the relationship between speed of rotation and negative pressure produced using a spindle according to the invention.

Referring now to FIG. 1, there is illustrated, a hollow cup-shaped rotor 1 having a central vertical axial shank portion 2, the rotor being rotatable in bearings 3 carried by a support 4. Within the cup-shaped rotor 2 is a hollow stator 5 supported on the shank 2 by bearings 6, and prevented from rotating by magnets 7 and 8 mounted on the stator 5 and support 4 respectively. A hollow shaft 9 extends vertically upwardly from the stator 5, and forms a downstream portion of a continuous conduit illustrated by the general reference numeral 10. An axial continuation 11 of the hollow shaft 9 extends into the shank 2 of the rotor 1 and the conduit further includes an elbow portion 12, and an oblique portion 13 which extends radially upwardly at an angle to the axis. Finally, the continuous conduit 10 is completed by a portion 14 which extends parallel to the axis of the rotor. The portions 11, 12, 13 and 14 of the continuous conduit are formed on the rotor and rotate with the latter.

At its upper end, the rotor is provided with a take-up member in the form of a downwardly convergent annular conical shell member 15. Surrounding the shaft 9 is a resilient ring 16 which serves to centre a yarn package 17 on the shaft 9.

Fitted at the upper end of the yarn package is a magnetic tension means 18 which tensions yarn leaving the package and entering the inlet at the upper end of the hollow shaft 9.

Mounted immediately above the yarn tensioning device, on the axis of the spindle, is a yarn guide 19. In operation, yarn leaves the package 17, passes through the yarn tensioning device 18, and downwardly through the hollow shaft 9. It then passes through the continuous conduit 10, makes an enclosed arc around the shell member 15 and finally passes up through the yarn guide 19. Rotation of the rotor causes a negative pressure to be produced in the continuous conduit 10.

FIG. 2 illustrates a modified form of rotor. In this embodiment, the rotor 20 instead of having an integral shank, is formed with a removable tube 21, of hardened steel, corundum, ceramic or similar material.

At its lower end, tube 21 is formed with two semiovoidal symmetrical elements 22, 22', these respectively being formed with grooves 23, 23. Resting in a recess 24 in the rotor 20 is a cup 25 which, together with the grooves 23, 23 forms the equivalent of the elbow portion of the continuous conduit 10 of the embodiment of FIG. 1. The cup 25, and the tube 21, are secured in place on the rotor by a plate 26, which is formed with a pair of apertures in alignment with the grooves 23, 23'. Inserted into these apertures are tubes 27, 28 which extend at an angle to the axis of the rotor and constitute the downstream end of the continuous conduit of this embodiment. All the components are disposed symmetrically to provide for dynamic balancing of the rotor.

By providing a second tube, it is possible to increase the aspiration rate, and to control it as desired. It is possible to design in a similar manner spindles having a multiplicity of such tubes which are distributed uniformly around the axis of the spindle. A particularly preferred embodiment is a spindle having three tubes, disposed at 120 relative to one another around the axis of the spindle.

In order to illustrate the negative pressure produced, a spindle having three such equi-angularly disposed tubes was provided with a water pressure gauge at the spindle inlet. For different speeds of rotation, the corresponding negative pressures were measured, and were plotted on a graph, as illustrated in FIG. 3. The abscissa of this graph illustrates the speed of rotation, measured in units of 1000 r.p.m. while the ordinate expresses the negative pressure measured in millimetres of water. The curve I illustrates the result with two of the outlet orifices blocked, and one open, while the curves II and III illustrate the operation with two and three orifices open respectively. In each instance, the yarn travels through the open or one of the open orifices.

It will be seen that, by using a spindle having a plurality of conduits, it is possible, with the same speed of rotation to produce a suction effect as desired, simply by blocking one or more of the outlet ducts.

The advantages of the present invention will be more apparent from the following examples.

EXAMPLE 1 A spindle having three equi-angularly disposed continuous conduits, and the total weight of which was 7.4 kilograms was used. The diameter of the cylindrical portion of the rotor was 14.5 centimetres, and the maximum diameter of the conical takeup element was 16 centimetres. The height of the spindle from the rotor base to the uppor portion of the shell element, was 23.5 centimetres. The total height depends on the height of the package used, and the package carrying tube, corresponding to the tube 9 of FIG. 1, was suitably chosen.

A spindle carrying a cop 30 centimetres high, which carried a 1 kilogram package, was mounted on the spindle, which was rotated 9200 r.p.m. The yarn being twisted was an ethylene polyterepthalate 65 denier, 33 filaments ply yarn, the initial twist of which was 20 turns per metre (S-twist). The yarn was twisted in such manner as to obtain a final S-twist of 1100 turns per metre, the magnitude of the encircled are being two thirds of a turn. For winding on velocity of 16.7 metres per minute, the tensioning of the yarn was 11 grams, with a tension amplitude divergency of 10.5 gram.

EXAMPLE 2 In this example, the spindle and the mode of operation was identical to that of Example 1. In this Example, a polyhexamethylene adipamide 70 denier, 23 filaments ply yarn was twisted, the initial twist of which was 20 turns per metre (Z-twist) in such manner as to produce a final Z-twist of 500 turns per metre. The yarn embraced the shell member by two thirds of a turn, and the winding on velocity of this was 37 metres per minute, the tension in the yarn being grams with an amplitude divergence of $0.5 gram.

EXAMPLE 3 In this example, the twisting was effected on a cellulose acetate 75 denier, 24 filaments ply yarn which had no initial twist, on a spindle generally similar to that used in Example 1. -It was modified in such a manner that it was capable of receiving a package on a bobbin, the cup on the spindle being U-shaped in cross-section, having a diameter of 30 centimetres, and a height of 15 centimetres. A 12 centimetres high and 26 centimetres in diameter bobbin carrying a 2.5 kilogram package was used. With a winding on velocity of 37 metres per minute, and an encircled arc of three quarters of a turn, tension was 13 grams, again with an amplitude divergence of :05 gram.

In the above examples the yarn shell member was located at the upper portion of the spindle. Of course, it would be equally possible to have the shell member at the lower portion of the spindle.

With the spindles of the present invention, the speeds of rotation of the spindle corresponding to the normal industrial speeds, generally low winding on tensions, with practically negligible tension amplitude of divergence were obtained. This is of very great importance, since such tension divergence leads subsequently to defects in the final product, such as stripyness in dyeing.

Furthermore, conventional spindles can readily be adapted or fitted to provide spindles according to the present invention. The adjustments required to accommodate diiferent operating conditions, are extremely simple, since it is only necessary, practically speaking, to modify a single parameter.

The spindle of the present invention, furthermore, permits the twisting of packages of widely varying types and shapes, notably those of large dimensions, with tall packages such as cops, or wide packages such as those comprising artificial or synthetic yarns obtained by winding on at high velocity by peripheral driving following the spinning operation.

We claim:

1. A double twist spindle comprising, in combination:

(a) a hollow shaft forming a support for a yarn pack- (b) an inlet at one end of said shaft;

(c) yarn tensioning means at said shaft inlet;

(d) a rotor, rotatable with respect to a package supported on said shaft, about the axis of said shaft;

(e) a continuous conduit rotatable with said rotor and positioned to receive yarn fed from said package, via said inlet;

(f) an outlet to said continuous conduit, radially out-- wardly of said shaft; and

(g) a (take-up) shell member, carried by said rotor,

between said hollow shaft and said outlet of said continuous conduit, and positioned adjacent and at the level of said outlet, whereby yarn leaving said outlet describes an enclosed are about said (take-up) shell member.

2. A double twist spindle as claimed in claim 1, wherein said yarn tensioning means is a magnetic tensioning means.

3. A double twist spindle as claimed in claim 1, Wherein said rotor comprises a cup-shaped member, having a hollow axial shank thereto, and wherein said continuous conduit is formed by said hollow shank and by at least one tube connected thereto and extending along said cupshaped member.

4. A double twist spindle as claimed in claim 3 and including a plurality of tubes disposed in equi-angular relationship around the spindle axis.

'5. A double twist spindle as claimed in claim 3 wherein a removable yarn guide is positioned to guide yarn between said hollow shank and said at least one tube.

6. A double twist spindle as claimed in claim 1 wherein the shell member includes a conical take-up surface.

'7. A double twist spindle as claimed in claim 6 wherein the shell member is located at the upper portion of said spindle.

8. A method of double twisting a yarn, in which the yarn is fed through a hollow rotatable double twist spindle and passed through a yarn guide to form a balloon, comprising the steps of:

(a) regulating the tension of a yarn at the inlet to said spindle;

(b) passing the yarn through a continuous conduit rotatable with said spindle and positioned to receive yarn via said inlet, the continuous conduit having an outlet radially outwardly of the spindle axis; effective to produce a controlled aspiration of the yarn in said spindle; and

(c) picking up the yarn on a shell member carried by the spindle in such manner that the yarn describes thereon an encircled arc of between a quarter of a turn and one turn.

References Cited UNITED STATES PATENTS 1/1916 Evans 57-73X 5/ 1936 Freund 57-73X 11/1949 Uhlig 57-5886 FOREIGN PATENTS 12/1951 France 57-5886 10/ 1962 Germany 57-5836 US. Cl. X.R. 

